OnePlus today released OxygenOS 1.0.2 for the OnePlus One containing patches to fix the Stagefright vulnerability.
OxygenOS is OnePlus’ own version of Android for the One. The company was forced to release the OS after a tiff with Cyanogen OS last year. It is also the default OS in the company’s 2016 flagship killer: the OnePlus 2.
Since OxygenOS on the One does not support OTA updates, OnePlus One owners who are running the custom ROM on their device will have to manually install the update on their device. Installing the update will not wipe the phone, but it is still recommended to create a backup just in case things go wrong.
You can find the download link of Oxygen OS 1.0.2 here, while the installation instructions can be found here.